Insulator.



A. M. BOURKE.

INSULATOR. APPLICATION FILED JULY ze, 1910.

Patented Mar. 19, 1912.

ALEXANDER MORRISON .BOURKE 0F MAITLAND', NEW SOUTH WALES, AUSTRALIA.

INSULATOR.

Specification of Letters Patent.

Patented Mar. 19,1912.

Application led July 26, 1910. Serial No. 573,837.

To' all whom t may concern:

.Be it known that I, ALEXANDER MORRISON Bomann, a subject ofthe King of Great Britain, residing at Maitland, New South Wales, Australia, post-otiice address care of Joseph Turner, Esq., BerryPark Estate, Thornton, Maitland, New South Wales, Australia, mining engineer and Surveyor, have invented a new and useful Improvement in and Relating to Insulators, of which the following is a specification.

This invention relates to insulators for telegraph, telephone and like wires, and it has more particular reference to that type or class'of insulator provided with a. groove for the reception of the wire, and a gripping device arranged approximately in the center thereof for-firmly securing the wire to the aforesaid insulator.

Gripping devices of a more or less complicated nature have been employed or suggested heretofore, having for their primary object the retention.of the wire in place without bending, but I have found in prac,

tice that the danger,.or liability to fracture or deformation is-very far from being eliminated.

. The object of my invention is to overcome the foregoing objectionable disadvantages in an extremely effective manner while at the same time materially improving the construction of the insulator, increasing its efficiency and durability, as well as providing for its easy adjustment laterally.

With the foregoing objects in view my invent-ion primarily consists in providing the insulator with a slot-having oppositely situated outsets therefrom and a groove at its base for the part reception of the wire, said slot being adapted to receive acorrespondingly shaped wedge piece or gripping device furnished at its. underside with a groove in register with that at the base of the aforesaid slot and lat its upper face with a. projection and means such as a screwed cap or cover for locking the wedge piece in position.

A subsidiary feature of the -invention consists in an improved construction olf-'the insulator stud or shank whereby lateral adjust-ment is readily effected.

In order that my invention may be clearly understood and carried into practical eect I will now describe the same with reference to the accompanying sheet of drawings which illustrate two embodiments thereof.-

`down or inclined toward Figure `1 is a central verticalI sectional view of a double shed insulator taken at right angles to the direction of the.wire receiving slot. Fig. 2 is a plan of the same with the cap and wedge piece removed for the sake of clearness. Fig. 3 is a Similar view to Fig. l of a slightly modified construction of insulator. Fig. 4 is an isometric view to an enlarged scale of the wedge piece hereinafter more fully described.

Like reference numerals designate the saine or similar parts in the several igures.

The insulator' which may be constructed of porcelain, stoneware or other suitable material and lead or leadless glazed is formed with a wide transverse slot 1 in its upper part or neck portion 2, said slot 1 being arranged diametrically across the neck portion 2 and preferably approximately rectangular in cross section. This slot 1 isA provided cent-rally of its length with two oppositely situated outsets 3, 3, rect-angular in plan, for example, and somewhat tapered the base ofthe said slot 1, as will be-clearly seen from Figs. 1 and 2. The cross sectiony of the outsets 3, 3, may, obviously, be other than rectangular and I do not limit myself to the section illustrated.

Diametrically across the insulator and at the base of the slot 1, I form an approximately semi-circular groove 4 the bottom of which preferably lies in a plane coincident with that of the upper outer surface of the outer shed 5 of .the insulator. This groove 4 (formed in theV body of the material as shown in Figs. 1 and 3) is preferably ofa cross section to receive the standard size of wire 6.

7 is the wedge piece or gripping device which is made of a cross section corresponding with that of the slot land a length somewhat less than the diameter of the neck portion 2 as will be clearly Seen on referencel to Fig. 3. This wedge piece or gripping 'device 7 is preferably formed of metal and provided with tapering projections 8, 8, adapted to register with the aforesaid outsets 3,3. At the underside of the gripping device 7 there is provided an approximately register with the `groove 4 and` when the parts are assembled to constitute therewith the retaining means for the wire 6. The groove 9 may be serrated or longitudinally ribbed to insure a firm grip upon the wlre,

vsemi-circular groove 9 which is arranged to and the wedge piece 7 may in exceptional .cases of very light wires be made of the same material as the insular body. At the top of the wedge piece 7 I provide a hemi spherical or other suit-ably shaped projection 10 for the purpose hereafter to be eX- plained.

The upper or neck portion 2 of the insulator is screw threaded on its outer surface to receive a correspondingly threaded cap or cover 11 of porcelain, stoneware, or other suitable material or metal, Axially within the crown of the cap or, cover 11 I form a hemispherical or other suitably shaped recess 12 in which beds the projection 10 on the wedge piece above referred to; or, the recess may be formed in the top of the wedge piece 7 and the projections upon the underside of the cap or cover, anl arrangement readily understood without further illustration or description.

13 is a washer of suitable material for insuring a damp proof joint between the insulator and the cap or cover 11.

Insulators embodying my invention are preferably attached to the supporting arms of the telegraph or like poles or 'their equivalent in the following manner :.-The metal shank or supporting stud 14 is provided with a rectangular shaped head 15 arranged to traverse acorresponding'ly shaped channel formed inv the cross-bar 16 constructed as heretofore well known, and be locked in the desired position by means of a set screw or lock nut 17 as will be clearly understood from Fig. 1. Or, I may form the shank or supporting stud 14 and head 15 integrally with the insulator body and concentric with the inner shed. 18 of said insulator as shown in Fig. 3 and fix it in place in the cross bar 16 in any of the well known ways, such, for instance, as by clamping or pinning. In cases where the wire 6 is other than standard gage I wrap it around with attened copper wire where it beds into the insulator, said method of packing y the wire I find being exceedingly effective for preventionof longitudinal displacement.

Although I'have described my invention in considerable detail it will be apparent that modification as regards the shape and size of the wedge piece 7 and slot 1 may be made to adapt the improvements to fuse insulators as well as insulators provided with a side button or branch for turning the wire into a building or around a sharp corner without departing from the essential member adapted to fit in saidv wider portion,

a plurality of lugs carried by said wedge member adapted 'to engage in said recesses,

and a cap member. adapted to lit over a por?A tion of said body member and force'said wedge member downward upon. said wire for clamping, as set forth; j

2. In an lnsulator,- a body member provided with external screw threads and having a diametrical slot therein-for the recep-4 tion of a wire, said recess being provided with a broadened portion running partially the length thereof, and having recesses formed in the opposite walls of said broadened portion, a wedge'member adapted to .lit in said broadened portion, a plurality of" oppositely extending lug members carried by said wedge member and adapted to be received in said recesses, and a 'cap member 'adapted to be engaged by said external screw threads for retaining and exerting a downward force upon said wedge member,

for clamping the wire, as set forth.

3. In an insulator, the combination with j a supporting member, of an' insulator, means for retaining said insulator on said supporting member, said insulatorcomprising, a body portion provided with a diametrical slot for the reception of the wire, said slot 4being provided with a wider portion, vand having a plurality of recesses in the walls of said wider portion,a'wedge member adapted to lit in said broader portion, a plurality 0f lug members carried by said wedge member and adapted to t in said recesses, and a cap member adapted to be engaged by said body member for retaining and exerting a clamping force upon said-wedge member, as set forth.

In witness whereof I have hereunto set .my hand in the presence of two witnesses.

ALEXANDER- 'MORRISON BOURKE. Witnesses:

E. LAURENCE H.' ELLIOTT, J. OSWALD FARRER. 

